Specificity of autologous antibody binding to phenylhydrazine-treated human erythrocytes: implications for models of red blood cell aging.

A fundamental difficulty in the study of red cell senescence has been that of isolating a population of cells that have been aged in vivo. It has been proposed that the induction of Heinz body formation through the use of oxidizing agents, including phenylhydrazine, can provide a model for elucidating mechanisms of normal red cell aging. In an effort to evaluate the applicability of this model, we examined the nature of autologous antibody binding to phenylhydrazine-treated cells. Using both radioisotopic and immunofluorescent probes, we confirmed the previous observation of increased immunoglobulin G (IgG) binding to phenylhydrazine-treated cells. However, further analysis of the cell population indicated that the majority of the IgG bound to cells that had suffered severe membrane lesions, allowing access to intracellular consituents. Elution and analysis of the bound autologous IgG confirmed that it showed specificity for some of these intracellular constituents as well as for the surface epitopes available on intact cells. We conclude that phenylhydrazine treatment is a problematic model for study of red blood cell aging mechanisms, because the binding of autologous IgG appears to be limited to a small population of severely damaged cells.